Missing here is having clarity on how to handle confirmation and related logistics. I used to think it was me and not having the right wording (so I've tried different ways of asking), but some of the experienced guys seem to know exactly what I'm asking and have a protocol for this---usually they will plan to message the day before or the day of the appointment to confirm and provide location, if they're hosting. If they do that but have to adjust a little at the actual appointment, things go well. Ditto if they suggest my messaging the day or morning before.
I had made an appointment recently with a visitor. The communication had gone OK and he even sent some pics after making the appointment. But then I heard nothing the morning of the multi-hour appointment, so I took the initiative to message him about 4 hours ahead. Nothing until 45 min before the appointment. I've had similar scenarios in the past and have gone along with them, but usually it's been associated with a not-great appointment. This time I said, "sorry, it's gotten too late and I have other plans". He offered new times--maybe a half our or hour later, but I stuck to my guns. I pointed out that I treat this like any other professional interaction and that by the time he responded, I had no idea whether I needed to prepare and I also had no idea where I had to go. I told him I would have been more willing and able to be flexible if he had given me more notice. He came back with saying that I was in his schedule and claimed that 45 minutes was enough (not if I have no idea where I have to go). Interestingly, there was no apology and the excuse for being late (going to the gym) didn't preclude looking at messages earlier. There also was no offer to schedule on another day. My guess is that he had a late night (based on his last RM login) and a long, disorganized trip to the gym. None of that boded well for a good appointment.
So...while most of the questions raised here make sense, a good profile covers most of them, and what may be pivotal is how they want to handle confirmation and ultimately handle the time leading up to the actual appointment. If they can't articulate that, they probably aren't thinking about how best to organize and carry out their work.